1. Field of the Invention
The present invention relates to a device for increasing the volume or capacity of a container provided with an upper opening having an upper edge, which comprises a plurality of extension elements pivotally mounted on the upper edge of the opening, wherein the extension elements form a cover at least partially closing the opening when lying flat in a closing configuration and form an enlarging extension for the container in an erect filling configuration and neighboring extension elements are pivotally connected with each other.
2. Description of the Related Art
The grain tank of a combine harvester is provided with a grain tank extension, which comprises a plurality of side walls. The side walls are movable from a closed configuration into an opened configuration, and from the opened configuration to the closed configuration. During travel on a road the side walls are folded closed to form a cover to save space so that the combine harvester does not exceed its proscribed total height. In operation on a field the side walls are raised in the opened configuration so that the grain tank volume is increased and the grain tank needs to be emptied less often and at greater time intervals.
DE 100 51 096 A1 discloses a device for increasing container capacity, which comprises four walls, which are movable between an operating configuration, in which they form a laterally closed enclosure, and an out-of-operation configuration. Two walls opposite to each other are made from a rigid material and are pivotable. The other two walls opposite from each other are made from a flexible material and are also pivotable. The walls made from the flexible material are connected at their ends with the walls made of the rigid material, so that in the operating configuration a laterally closed enclosure is formed. The rigid walls are raised by means of a filled pipe, which is automatically raised and lowered with a drive. The flexible walls are raised together with the rigid walls into the operating configuration and folded together again because of their flexibility, when the rigid walls are again folded into the out-of-operation condition. In the operating configuration the rigid walls are folded out past the vertical position, while the flexible trapezoidal walls are oriented vertically when the rigid walls are completely folded out. The disadvantage of this device is that the flexible walls are very strongly stressed or loaded by the lateral pressure of the grain tank contents. The flexible walls are thus not suitable for this sort of use and wear out more than average.